Automatic accumulating elevator for automation



R. BROSER May 28, 1968 AUTOMATIC ACCUMULATING ELEVATOR FOR AUTOMATION 2 Sheets-Sheet 1.

Fild Oct. 26, 1967 37A /0 IV.

S AT/OA/ N0. .3

STAT/0N Na. 2

INVENTOR RICHARD BROSER BY M1440,

ATTORNEYS R BROSER May 28, 1968 AUTOMATIC ACCUMULATING ELEVATOR FOR AUTOMATION Filed Oct. 26, 1967 2 Sheets-Sheet 2.

Fl G. 3

INVENTOR RICHARD BROSER BY 16am, f

FIG-2 ATTORNEYS United States Patent 3,385,419 AUTOMATIC ACCUMULATING ELEVATGR FOR AUTOMATION Richard Broser, Royal Oak, Mich., assignor to Accum-Matic Systems, Inc., Warren, Mich.

Continuation-impart of application Ser. No. 584,445,

Oct. 5, 1961. This application Oct. 26, 1967, Ser.

11 Claims. (Cl. 198-225) ABSTRACT OF THE DISCLOSURE An automated lift device for a series of parts which includes upon a framework opposed pairs of spaced pivotal part holders in the path of upward lifting movement of the parts and temporarily displaceable thereby, together with a power reciprocated transfer bar bearing a series of opposed pairs of longitudinally spaced pivotal part lifting dogs, which have an operative lift position and an inoperative clearance position, together with a part sensing device adjacent each station to automatically determine whether the lifting dog is operative or inoperative.

This invention relates to an automated accumulating lift mechanism, and is a continuation-in-part of my copending United States application Ser. No. 584,445, filed Oct. 5, 1966, entitled Automatic Accumulating Transfer Mechanism.

It is an object of the present invention, to provide an automated accumulating lift mechanism upon which a series of spaced parts are movably mounted and progressively elevated from a lower-most station to a higher station and with automatic means by which the conveyor dogs for lifting a part from one station to the next station there above controlled automatically 'as to whether such dogs should be operative or inoperative.

It is an object of the present invention to provide upon the present lift mechanism a series of workpiece supporting or locating stations which are longitudinally spaced apart and incorporating a transfer mechanism employing opposed lifting dogs in pairs longitudinally spaced corresponding to the spacing of the stations and by which upon reciprocal movement of the transfer mechanism, dogs if in operative position, will lift the parts from one station to another and if in inoperative position will not lift the parts to a succeeding station.

It is a primary object of the present inevntion to incorporate in the present lift mechanism automatic means by which positioning of the lifting dogs into an operative lift position will be determined by the need for lifting a part from one staton to the next in the existence of an open space or station to which the part can be lifted.

It is another object of the present invention to provide an automatic means by which the lifting dogs on retraction of the conveyor or transfer bar are automatically rendered inoperative in which position they will remain unless a further sensing mechanism controls the said dogs for tipping the same back to operative lift position.

These and other objects will be seen from the following specification and claims in conjunction with the appended drawings in which:

FIG. 1 is a side elevation-a1 view of the present automated accumualtin g lift mechanism.

FIG. 2 is an end elevational view thereof.

FIG. 3 is a top plan view thereof.

It will be understood that the above drawing illustrates merely a preferred embodiment of the invention, and that other embodiments are contemplated Within the scopeof the claims hereafter set forth.

Referring to the drawings the present automated ac- "ice cumulating lift mechanism has provided upon any support base 11 an upright frame 12 which includes a pair of spaced side plates 13 connected thereto, FIG. 3. A series of opposed pairs of vertically spaced part holder arms 17 are pivotally mounted intermediate their ends at 18 upon the adjacent side plates 13, each having a cradle means or recess 16 adjacent their one ends adapted to supportably receive the parts P, and located with respect to the side plates 13 and pivoted against stops 19, corresponding to the designated station 1, station 2, station 3, and station 4, for illustration.

The lower-most pair of holder arms are designated at 14 and are not pivotally mounted but are fixedly secured as by fasteners 15 to the adjacent side plates shown, being the part holder arms which receive parts from another source, such as a conveyor line for elevation using the present apparatus, and thus the part holder arms 14 are rigidly mounted and nonpivotal.

As to the additional pairs of part holder arms 17 corresponding to the stations 2, 3, and 4, the corresponding stop pins 19 project inwardly from the adjacent side plates 13 for retaining the holder arms 17 in the part support position shown, with the parts nested within the cradles 16, FIG. 1.

The said pivotal holder arms 17 are adapted for tilting momentarily by the said parts P, respectively, as the same are moved upwardly so that the said holder arms 17 tilt out of the path of upward movement of the said parts until the part has passed and then the said part holder arms 17 return by gravity to the part support position shown to supportably receive the part which has been lifted to the corresponding station or directly thereabove and released by the corresponding lifting dogs 27 as hereafter described.

Upright guide support 20 secured to and arranged inwardly of frame 12., FIG. 3 extending throughout the height of the said frame and in the illustrative embodiment of one form of guide means includes the elongated dovetail 21, which is slidably received within a correspondingly shaped dovetail slot 23 formed throughout the length of the vertically adjustable transfer bar 22.

Said transfer bar is adapted for continuous vertical reciprocation under the control of the hydraulic or pnuemtaic motor 25 whose piston rod 24 is connected with the transfer bar and the said motor is controlled by a suitable control valve 26 or other control automatically operated for effecting continuous reciprocation of the said transfer bar 22 within and with respect to the stationary guide support 20 within the lifting frame.

A series of opposed pairs of part lift dogs 27 are pivotally mounted in spaced relation as at 28 upon said transfer bar and are spaced longitudinally thereon corresponding to the spacing of the respective stations 1, 2, and 3, and are adapted for reciprocal movement continuously between the adjacent stations and when in operative position adapted to lift the parts P from one station to the next succeeding station thereabove.

Each of the said dogs 27 has a corresponding part sup port cradle recess 31 so that a pair of opposed spaced dogs are adapted to support a part P therebetween.

The dogs 27 have the operative lift position shown in FIG. 1 as well as the inoperative position shown on dotted lines rendered thus ineffective for a lifting operation despite and during continuous reciprocal movements of transfer bar 22.

With the dogs tilted to the inoperative position shown this corresponds to a part clearance position and thus with the parts supported upon the holder arms 17 continuous reciprocal movement of the corresponding dogs 27 will be ineffective for lifting the part from one station to the next succeeding station thereabove.

The pivotal mounting of the respective pairs of dogs 27 includes the arcuate opposed slots 29 extending through the respective dogs adapted to receive the transverse pins 30 which project through the said transfer bar and into the said slots to thus limit pivotal movement of the said dogs between operative position and inoperative position as shown in FIG. 1.

Means are employed in the present apparatus for automatically tilting all of the said dogs to inoperative position on each retraction of the said transfer bar.

For this purpose one of the lower-most pair of dogs 27 has secured thereto cam having a rearwardly and outwardly tapered cam surface. A retractable spring biased button 36 is mounted on and projects inwardly of one of the said side plates 13, FIG. 2, and is normally in the path of upward movement of the said lower-most dog 27 and its cam 35. On such upward movement of the dog, when said cam passes pin 36, it causes momentary retraction of said pin, which is biased outwardly. On the return movement of the dog on return movement of the transfer bar 22, the said button 36 operatively and retainingly engages the cam 35 causing the corresponding pair of dogs to rotate in unison to the inoperative position shown.

A movable means is provided by which the said last or lower-most pair of dogs is connected to each of the spaced pairs of dogs 27 thereabove so that when the lowermost dog 27 is tilted to inoperative position by virtue of the stop pin 36 and cam 35, each and all of the corresponding dogs 27 will be also tilted from operative to inoperative position.

For this purpose there is provided a series of longitudinally extending trip arms 32 which are aligned vertically, FIG. 2, and in engagement end to end and slidably mounted upon and along one edge of transfer bar 22. Each of the said trip arms intermediate its ends has a trunnion 33 which extends to the opposed pair of dogs 27 and is connected thereto by the transverse pin 34 which extends through the said trunnion or boss and into the corresponding dogs 27. The respective trip arms 32 are thus arranged end to end and thus a counterclockwise pivotal movement of the lower-most pair of dogs 27 to inoperative position causes a lifting of the connected trip arm 32 and a consequent and successive lifting of each of the trip arms 32 thereabove to activate the respective pairs of lifting dogs 27 tipping them all simultaneously from operative to inoperative position.

Thus, on the return movement of the lower most dogs 27 cam 35 engages the retractable button 36 anchored at 37 to a side plate and tilting the lower-most pair of dogs to inoperative position. Through the respective trip arms 32 each and all of the additional pairs of dogs 27 are simultaneously tilted to inoperative position.

Once the dogs 27 are in the inoperative position shown they will remain in that position until turned to an operative position by the automatic control now to be described, namely; sensing arm 38.

In connection with the respective stations 2, 3, and 4, there is provided adjacent thereto upwardly inclined part sensing arm 38, which arms as shown in FIG. 2 are pivotally mounted alternately upon the respective opposing side plates 13 as by pivot pins 39 with suitable spacers 40 employed. A series of stops 41 are applied to the frame 12 along its height and are adapted to engage as at points 42 the respective sensing arms 38, each of which will assume by gravity due to the off center pivot 39, the position shown in FIG. 1.

Each of the sensing arms 38 has a part detector cam face 43 adajcent its upper end as designated in dotted lines in FIG. 1 and adjacent its lower end has a laterally extending cam 44.

At least one of each opposed pair of cams 27 have projecting from their lower edge portions a corresponding cam roller so that if the sensing arm 38 is in the control position shown bearing against the stop 41 its cam 44 will be in the path of retracting movement of the respective cam roller 45 for tipping the dogs from the automatic inoperative position produced as above described to the operative position shown in FIG. 1.

It is understood that under sensing arm control 38 if the pair of dogs adjacent station 2 of FIG. 1 are cammed to the operative position shown, the remainder of the lift dogs 27 thereunder will be tipped to operative position, not by the corresponding sensing arm 38 but by virtue of the fact that the aligned trip arms 32 activated by the upper-most said pair of lift dogs which have been tilted cause all the remainder of the pairs of lifting dogs therebelow to be automatically tilted to operative lift position.

If, on the other hand, a part nests within the cradles 16 of the upper set of the support arms 17, then the sensing arm 38 will not be in the position shown but will be tipped to a dotted line position such as shown adjacent station 3, so that the corresponding cam 44 is out of registry with the dog cam roller 45 and thus on retracting movement of the transfer bar 22 the corresponding pair of lifting dogs at station number 3 will remain inoperative. This is because under the circumstances if the upper most part P has not been removed,

it has no place to go and thus it would be undesirable to have the pair of lifting cam 27 therebelow lift another part to the topmost station number 4, which would in effect possibly dump off the part P thereon.

That is why the sensing arm 38 will be retained by the top-most part P in a non-control or inoperative tilted position with its lower end spaced from the stop 41 and the corresponding pair of dogs 27 adjacent station number 3 will remain inoperative. As a part of the present invention it is contemplated that should any particular station be empty of a part P or the part P removed therefrom, as for example station number 3, or station number 4, then the corresponding sensing arm 38 with respect to that station would be permitted to tip by gravity to the control position so that for example if there is no part at station number 3, sensing arm will tip to the extreme position shown so that its lower cam 44 is in a control position or relative to the roller 45 to tip the dogs corresponding to station number 2 to a lift position, and this pair of dogs will cause through the trip arms 32 to tip the lifting dogs 27 therebelow also to lifting position.

Thus, at any point in the lifting operation regardless of the number of stations involved if any particular station becomes empty pairs of lifting dogs therebelow on the transfer bar will each and all be automatically tipped to a lift position for bringing up a part to the empty station and moving all of the parts therebelow upwardly one station to keep the conveyor full of parts at all times.

If a particular station is empty of a part the corresponding sensing arm will move to a control position so that the next pair of dogs therebelow will be automatically tilted to operative lift position and the process is repeated.

Upon at least one of the pairs of cams 27, being the one corresponding to the adjacent sensing arm 38, and in addition to the roller 45, there is provided an elongated cam plate 46, which under normal operations does not function. However, in a situation where the corresponding lifting dog has been previously tipped to an inoperative position and at the same time the corresponding sensing arm thereabove is retained in an operative position due to uncradling of a part at the station thereabove, then in that case normally speaking the cam 44 will block the upward movement of the dog 27, assuming that on some basis the dog roller 45 is positioned below cam 44.

Rather than to damage the assembly, the cam 46 on upward movement will register with the cam 44 on the sensing arm and will automatically tip the corresponding sensing arm 38 to an outward inoperative position to thus avoid damage to the assembly.

Having described my invention reference should now be had to the following claims.

Iclaim:

1. In an automated accumulating lift mechanism upon which a series of spaced parts are movably mounted;

an upright frame including a pair of spaced side plates;

a series of opposed pairs of vertically spaced part holder arms on said side plates, all but the lower most pair being pivotally mounted thereon and having cradle means for supporting a part therebetween;

a stop for retaining said pivotal holder arms in a normal part support position, at locations corresponding to a series of part stations along said side plates;

said pivotal holder arms adapted for tilting momentarily by said parts respectively and out of the path of upward movement thereof, and returning by gravity to part support position to receive said parts;

an upright transfer bar guidably mounted on said frame;

reciprocal power means connected to said transfer bar;

a series of opposed pairs of part lift dogs pivotally mounted on said transfer bar longitudinally spaced thereon corresponding to the spacing of said stations and reciprocally movable continuously between adjacent stations respectively;

each dog having a cradle means for supporting a part between each pair of dogs;

said dogs having an operative part engaging position and pivotal in unison to inoperative part clearance position;

means to automatically tilt said dogs to inoperative position on retraction of said transfer bar;

an upwardly inclined part sensing arm pivotally mounted off center upon one of said side plates adjacent some of said stations and extending to the next station thereabove;

engageable at its upper end and movable by a part at one station for maintaining said sensing arm in an inoperative position, and normally pivoted by gravity to a control position;

a control cam at the lower end of said sensing arm adjacent the next preceeding station;

and a cam roller on one of each pair of dogs operatively engageable with said control arm on retraction of said transfer bar when said sensing arm is in control position to automatically pivot the corresponding adjacent pair of dogs into operative part lift position.

2. In the lift mechanism of claim 1, the mounting of said transfer bar including an upright guide support on said frame;

and cooperating means on said transfer bar slidably interconnected with said guide support.

3. In the lift mechanism of claim 1, a stop on said frame engageable with each sensing arm limiting its pivotal movement into operative control position.

4. In the lift mechanism of claim 1, a part detector cam face on said sensing arm adjacent its upper end normally lying in the path of upward movement of said parts.

5. In the lift mechanism of claim 1, the mounting of each pair of dogs including a pin on and extending transversely from opposite sides of said transfer bar;

there being a pair of opposed arcuate guide slots through said dogs spaced from their pivotal mounting receiving said pin to limit pivotal movement of said dogs.

6. In the lift mechanism of claim 1;

a series of longitudinally extending trip arms aligned and in engagement end to end slidably mounted upon said transfer bar, each trip arm intermediate its ends pivotally joined to and interconnecting a pair of opposed dogs for movement in unison;

whereby if one pair of dogs is pivoted to inoperative position, all pairs of dogs thereabove will also be tilted to inoperative position;

and whereby if one pair of dogs is pivoted to operative position, all pairs of dogs therebelow will also be pivoted to operative position.

7. In the lift mechanism of claim 6, the pivotal connection of each trip arm to a pair of dogs including a trunion on said trip arm intermediate its ends extending between and engaging a pair of opposed dogs;

and a pin extending through said trunnion and into said dogs and pivotally interlocked therewith.

8. In the lift mechanism of claim 1, said means for tilting said dogs to inoperative position including a cam laterally mounted on a lower most dog and having a rearwardly and outwardly tapered cam surface;

a retractable spring biased button upon and projecting inwardly of an adjacent side plate normally in the path of upward movement of said dog and retractable thereby;

said button operatively and retainingly engaging said dog on retraction of said transfer bar, and movable means connecting said last dog to all dogs upwardly thereof for automatically tilting them to inoperative position.

9. In the lift mechanism of claim 8, said movable means including a series of longitudinally extending trip arms aligned and in engagement end to end slidably mounted upon said transfer bar, each trip arm intermediate its ends pivotally joined to and interconnecting a pair of opposed dogs for movement in unison.

10. In the lift mechanism of claim 1, a series of longitudinally extending trip arms aligned and in engagement end to end slidably mounted upon said transfer bar, each trip arm intermediate its ends pivotally joined to and interconnecting a pair of opposed dogs for movement in unison whereby if one pair of dogs is pivoted to inoperative position, all pairs of dogs therebelow will also be tilted to inoperative position;

automatic sensing arm controlled pivotal movement of a dog to operative part lift position causing a corresponding movement of the connected trip arm and all trip arms therebelow tipping all succeeding pairs of dogs into operative lift position.

11. In the automated lift mechanism of claim 1, an elongated safety cam on those dogs having a cam roller, adapted for registry with the sensing arm cam when said sensing arm is in an operative position in a collision path, to automatically tilt said sensing arm to inoperative position.

References Cited UNITED STATES PATENTS 3,127,981 4/1964 Sharpe 19822l EDWARD A. SROKA, Primary Examiner. 

